1. Field of the Invention
The present invention relates to an electric-component feeder which supplies, from a component-supply portion thereof, a plurality of electric components (e.g., electronic components).
2. Discussion of Related Art
There is known an electric-component feeder which includes a component conveying device that conveys a plurality of electric components, one by one, to a component-supply portion of the feeder, and which is used in, e.g., an electric-component mounting system. Each electric component supplied to the component-supply portion is taken by a component taking device, and is mounted on a component-mount place on a circuit substrate so as to produce an electric circuit. The conventional component taking device includes a component positioning member that accurately positions each electric component, which is mounted on the circuit substrate. Alternatively, from the electric-component feeder, each electric component is sucked and taken by a suction nozzle and, during a time duration in which the electric component is conveyed by the suction nozzle to the component-mount place on the circuit substrate, an image of the component is taken by an image taking device and the taken image is processed to detect a positional error of the component held by the nozzle. In the latter case, after the suction nozzle and the circuit substrate are positioned at a relative position that has been modified by the detected positional error, the electric component is mounted on the circuit substrate.
However, in the case where a component positioning member is used to position each electric component, it is needed to change the current component positioning member with a different component positioning member corresponding to the size or sort of each electric component. Thus, the component taking device needs to have a complex construction, and additionally it needs a long time to change the component positioning members. This leads to making it difficult to increase the operation efficiency. Meanwhile, in the case where the taken image is processed to detect the positional error of the electric component held by the suction nozzle, it is needed to take the image of each electric component and complete the processing of the taken image during the time duration from the time when the component taking device takes the electric component from the electric-component feeder to the time when the taking device mounts the component on the circuit substrate. Thus, it needs a long time to take and mount each electric component. In addition, if an electric component is inaccurately positioned in the component-supply portion, the component taking device may fail to take the component.
It is therefore an object of the present invention to solve one of the above-identified problems by accurately positioning an electric component or supplying an electric component in a state in which a positional error of the component is known. This object may be achieved according to any one of the following modes of the present invention in the form of an electric-component feeder, each of which is numbered like the appended claims and may depend from the other mode or modes, where appropriate, to indicate and clarify possible combinations of technical features. It is, however, to be understood that the present invention is not limited to the technical features or any combinations thereof that will be described below for illustrative purposes only. It is to be further understood that a plurality of features included in any one of the following modes of the invention are not necessarily provided altogether, and that the invention may be embodied without some of the features described with respect to the same mode.
(1) An electric component feeder, comprising:
a component conveying device which conveys, in a component-convey direction, a plurality of electric components, one by one, to a component-supply portion of the feeder; and
at least one of (a) a positioning device which is provided in the component-supply portion of the feeder and which positions each of the electric components in each of the component-convey direction and a lateral direction perpendicular to the component-convey direction, and (b) a position detecting device which is provided in the component-supply portion of the feeder and which detects a position of each of the electric components.
In the present electric-component feeder, in the case where the electric component conveyed to the component-supply portion is positioned in each of the component-convey direction and the lateral direction perpendicular to the component-convey direction, a component taking device can take the electric component with reduced possibilities of failing to take, or can take the component being accurately positioned and mount the component at an accurate position on a circuit substrate. Meanwhile, in the case where the position detecting device is employed to detect the position of the electric component, the component taking device can be positioned relative to the electric-component feeder while the positional error is modified, before the taking device takes the component. This leads to reducing the possibilities of failing to take an electric component, or eliminating the need of taking and processing an image of an electric component after the taking of the component and before the mounting of the component and thereby improving the efficiency of mounting of electric components. In the case where both of the above-indicated two elements (a), (b), an appropriate one of the two elements can be selectively used depending upon an aim, or both of them can be used to obtain both of the effect of preventing failure to take and the effect of improving the mounting efficiency or the mounting accuracy.
(2) A feeder according to the mode (1), comprising the positioning device, wherein the positioning device comprises two positioning surfaces which face the component-convey direction and the lateral direction, respectively; and a close-contact causing device which causes a close contact between the each electric component and each of the two positioning surfaces.
Since the electric component is brought into the close contact with each of the two positioning surfaces facing the component-convey direction and the lateral direction perpendicular to the component-convey direction, respectively, the electric component can be accurately positioned.
(3) A feeder according to the mode (2), wherein the close-contact causing device comprises:
a pressing member which presses an opposite side surface of the each electric component that is opposite to an other side surface thereof facing one of the two positioning surfaces; and
a pressing-member driving device which drives the pressing member so as to press the opposite side surface of said each electric component and thereby cause the close contact between the other side surface of said each electric component and said one positioning surface.
(4) A feeder according to the mode (2) or (3), wherein the component conveying device comprises:
an endless, conveying belt which has a component-support surface supporting the electric components; and
a belt circulating device which circulates the conveying belt,
and wherein the close-contact causing device comprises the component conveying device that causes the close contact between the each electric component and one of the positioning surfaces that faces the component-convey direction.
If, after the component conveying device causes the close contact between the each electric component and one of the positioning surfaces that faces the component-convey direction, the electric component is brought into close contact with the other positioning surface facing the lateral direction facing the component-convey direction, the electric component can be easily positioned. Since the close-contact causing device comprises the component conveying device, the present electric-component feeder can enjoy a simple construction.
(5) A feeder according to any of the modes (2) to (4), wherein the close-contact causing device comprises a non-contact driving device which drives, without contact, the each electric component toward at least one of the positioning surfaces.
Since the electric component can be positioned without contact, the component can be effectively prevented from being damaged, and additionally the positioning device can usually enjoy a simple construction. The non-contact driving device may be a pressurized-fluid utilizing device or a magnetic-force utilizing device as described in the mode (6) or the following modes.
(6) A feeder according to the mode (5), wherein the non-contact driving device comprises a pneumatic driving device which pneumatically drives the each electric component toward the one positioning surface.
Preferably, the pneumatic driving device is provided by a device which causes a pressure difference on both sides of an electric component. For example, the pneumatic driving device may be a device which applies a pressurized air to a side surface of the electric component; a device which applies a negative pressure to a side surface of the component; or a device which applies the pressurized air and the negative pressure to opposite side surfaces of the component, respectively.
(7) A feeder according to the mode (6), wherein the pneumatic driving device comprises:
a suction passage which opens in the one positioning surface; and
a suction device which sucks air through the suction passage.
(8) A feeder according to any of the modes (2) to (4), wherein the close-contact causing device comprises a magnet which attracts the each electric component toward at least one of the positioning surfaces.
(9) A feeder according to the mode (8), wherein the magnet comprises an electromagnet; and an electric-current control device which controls an electric current supplied to the electromagnet.
When an electric component is attracted, the electromagnet is magnetized and, when the component is taken from the component-supply portion, the electromagnet is demagnetized. Thus, the electric component is effectively positioned and taken.
(10) A feeder according to any of the modes (1) to (9), comprising the position detecting device, wherein the position detecting device comprises an image taking device which takes an image of the each electric component.
The image taking device may be a device which takes an image of an electric component supported on a support surface, from above the component; a device which takes an image of an electric component held by a second conveying device, described later, from below the component; or a device which is described in the following mode.
(11) A feeder according to the mode (10), wherein the position detecting device further comprises a transparent support member which is formed of a transparent material and which supports a bottom of the each electric component, and wherein the image taking device takes, at a position below the transparent support member, an image of the each electric component supported by the transparent support member.
Since the image taking device takes an image of an electric component from below the component, a space above the electric-component feeder can be used to allow an electric-component receiving device or the like to perform its operation.
(12) A feeder according to the mode (11), wherein the transparent support member has a support surface which supports the each electric component, and a suction passage which opens in the support surface so as to apply a negative pressure to the each electric component and thereby attract the each electric component to the support surface.
Since the transparent support member applies a negative pressure to an electric component and thereby attracts the component, the component is effectively prevented from being moved on the transparent support member after the position of the component is detected.
(13) A feeder according to the mode (11) or (12), wherein the component conveying device comprises:
a first conveying device which conveys the electric components in an array; and
a second conveying device which takes the each electric component conveyed by the first conveying device and conveys the each electric component onto the transparent support surface.
According to this mode, the position of each electric component can be easily detected.
(14) A feeder according to the mode (13), wherein the second conveying device comprises:
a suction member which has a lower surface and a suction passage opening in the lower surface and which applies a negative pressure to the each electric component and thereby attracts the each electric component to the lower surface; and
a moving device which moves the suction member to a receiving position located in a downstream-end portion of the first conveying device and to a transferring position facing the transparent support member.
According to this mode, the second conveying device can enjoy a simple construction.
(15) A feeder according to the mode (14), wherein the moving device comprises:
a pivotable member which is pivotable about a substantially horizontal first axis line and which supports the suction member such that the suction member is pivotable about a second axis line parallel to the first axis line; and
a pivoting device which pivots the pivotable member about the first axis line.
Since the suction member can be moved to the receiving position and the transferring position, by a simple motion, i.e., the pivotal movement of the pivotable member, the moving device can enjoy a very simple construction or can be easily controlled.
(16) A feeder according to the mode (15), wherein the moving device further comprises:
a stopper device which engages, at at least opposite ends of a pivotal-movement range in which the pivotable member is pivotable, the suction member to stop respective pivotal movements of the suction member at the opposite ends of the pivotal-movement range; and
a biasing device which biases, at at least the opposite ends of the pivotal-movement range, the suction member in respective directions in each of which the suction member engages the stopper device.
Since the stopper device and the biasing device are employed, the suction nozzle is prevented from being unnecessarily pivoted at at least the receiving position and the transferring position, so that the suction member can reliably take or transfer an electric component.
(17) A feeder according to the mode (16), wherein the biasing device biases, in a state in which the pivotable member has been pivoted in a clockwise direction from a middle point of the pivotal-movement range, the suction member relative to the pivotable member in a direction in which the suction member is pivoted in a counterclockwise direction and biases, in a state in which the pivotable member has been pivoted in the counterclockwise direction from the middle point of the pivotal-movement range, the suction member relative to the pivotable member in a direction in which the suction member is pivoted in the clockwise direction.
According to this mode, the suction member can be prevented from being pivoted at each of the receiving position and the transferring position, and is allowed to be pivoted by the pivotal movement of the pivotable member between the receiving position and the transferring position.
(18) A feeder according to the mode (17), wherein the moving device further comprises a pivotable-member support member which supports the pivotable member such that the pivotable member is pivotable about the first axis line, wherein the suction member includes a first retaining portion positioned above the first axis line and the pivotable-member support member includes a second retaining portion, wherein the biasing device comprises a tension coil spring which is retained by, and between, the first and second retaining portions, and wherein the first and second retaining portions are positioned relative to each other such that at at least the opposite ends of the pivotal-movement range of the pivotal member, the suction member is biased, based on a tensile force of the tension coil spring, in respective directions in each of which the suction member engages the stopper device.
According to this mode, the biasing device recited in the mode (17) can enjoy a very simple construction.
(19) A feeder according to any of the modes (15) to (17), wherein the moving device further comprises a pivotable-member support member which supports the pivotable member such that the pivotable member is pivotable about the first axis line.